The modification of one or more properties, which necessarily results in modification of one or more conditions and/or structures, of materials and joints to provide materials and joints with specified physical, mechanical and structural properties, and the manufacture thereof, has generally been achieved by the application of continuous action, such as a form of energy, upon the material or by the stochastic transformation of this action upon the material. As such, various technologies have been developed to change or modify properties of materials and joints, and also to provide ways of manufacturing materials and joints which have specific properties. Many of these different technologies have developed in the area of generating technical effects that differ in results and goals, but are virtually united, irrespective of the technique, by a single unified concept of achieving specified properties and characteristics in the materials and joints. This concept has been based on the stringent process variations of the technology which are based, regardless of the methods of controlling operational procedure parameters of each process, on the direct non-adapted action upon the material so as to achieve the desired technical effect.
By convention, these technologies may be divided into two main groups: (1) volumetric and (2) localized. Volumetric technologies are those technologies accompanied by a simultaneous effect upon the entire product, material or joint, as for example in furnace heat treatment, bath galvanization, heat melting, and other processes. Localized technologies are those technologies accompanied by a local effect, i.e., an effect upon a specified area, on the product, material or joint, as for example in welding, ultrasonic impact treatment and other processes.
These technologies of the prior art are implemented based upon “stringent” algorithms that do not take into account the material's response to the effect of the action, i.e., the energy or technology. In some of these technologies, the process parameter deviation is monitored and the parameters are corrected so as to comply with a value previously specified. As such, the in-process control is not to control the change in the property, condition or structure of the material during the action, but to formally and stringently maintain the process conditions associated with these technologies.
For example, furnace heat treatment is an example of volumetric technology. During furnace heat treatment, a material is slowly heated, held at a phase transformation temperature and then slowly cooled. Long heat treatment runs stem from the need of a uniform distribution of heat within the furnace and within the material volume throughout the process. However, under actual conditions there are prerequisites for temperature gradients that, in turn, necessitate the material overheating to compensate for the unfavorable consequences of heat removal from the surface and near-surface volumes of the material. Thus, this typical volumetric process may be accompanied by excessive energy consumption, non-uniform heating and the formation of the attendant field of unfavorable residual stresses and deformations that are most often of tensile nature.
An example of a “stringent” localized technology is ultrasonic surface peening (termed “UP”). With this technology, a desired technical effect is obtained by surface plastic deformation under conditions of random single impacts that occur due to slight coupling between an ultrasonic transducer and an indenter under load. The stochastic nature of the random impacts during ultrasonic surface peening results in non-uniform surface treatment, the condition of which is controlled visually or using reference specimens until the material surface is completely covered with treatment marks. To accomplish this, the operator may use additional passes with a tool which can create conditions for excessive surface deformation and possible over-hardening. Thus, this localized technology process is accompanied by the problems of damaging the material mesostructure, providing non-uniform treatment at the level of limiting characteristics of various materials and a limited area of application that is restricted by the initial strength of the material, such as the initial strength of metal and alloy materials.
A common problem of “stringent” technologies defined in essence by the process algorithm is a possible disturbance of the specified relation between the effect upon the material, i.e., its parameters, and the expected effect, i.e., output characteristics of the material. This results in unjustified energy consumption, possible structural failures, non-uniform distribution of the treatment effects over the surface and within the volume of the material being treated, a great scatter of results and a possible deterioration of technology quality and reliability.
Other prior art technologies include, but are not limited to, pressure diffusion, diffusion welding, friction welding, ultrasonic welding, temperature diffusion, ultrasonic diffusion and impact diffusion. Pressure diffusion is a diffusion process caused by static loading sufficient for creating necessary plastic deformations in the materials being joined. Diffusion welding is pressure welding effected by the interdiffusion of atoms of the contacting materials with relatively long exposure to elevated temperatures and moderate plastic deformation. Friction welding is a process in which a weld area of a material is heated to a plastic state through the heat released in the friction of the interfaces of the material. Ultrasonic welding is pressure welding under ultrasonic oscillations, wherein the weld is made by a combined action of high-frequency mechanical oscillations, accompanied by the material heating in the weld area, and a compressive pressure applied perpendicular to the surfaces of the materials being joined. Temperature diffusion is a diffusion process caused by the exposure to elevated temperatures. Ultrasonic diffusion is a diffusion process caused by ultrasonic oscillations, specifically in applying coatings. Impact diffusion is a diffusion process caused by impact action.
Also known in the prior art are the basic mechanisms of fundamental metal structure transformation phenomena. These include, but are not limited to, plastic deformation, formation of the mesostructure, diffusion in metals and alloys, residual stress relaxation and corrosion. Plastic deformation is the residual change in the shape or dimensions of the loaded body of the material without discontinuity introduction. Formation of the mesostructure is where the metal structure material is at the level of comparatively coarse formations resistant to external actions with sizes between ˜10−3 and ˜10 μm. Diffusion in metals and alloys is the elementary process of displacement of atoms of crystalline material for distances greater than a lattice spacing. Residual stress relaxation is the gradual stress decrease with a constant total deformation, i.e., elastic and plastic deformation, of a material. Corrosion is a deterioration of a metallic surface under chemical or electrochemical environmental attack.
Also known in the prior art is the effect of ultrasonic treatment on the metal structure transformation mechanisms. Many properties are associated with the ultrasonic impact treatment technique. Some of these properties include improving the process of metal plastic deformation to a greater or lesser extent depending on the selected treatment variation; inducing considerable compressive stresses into the surface layer of a treated material, thereby improving the fatigue strength of the material; aiding in various processes of sizing and hardening treatments of materials; forming a honeycomb mesostructure in the surface layer of a treated material, thereby improving its strength properties; accelerating diffusion processes in metals; relaxing residual stresses in metal structures; and improving the corrosion resistance of the treated surfaces of the material. All of these properties associated with ultrasonic impact treatment of materials increase the quality and reliability of the treated material, thereby increasing the quality and reliability of structures and machinery components.
The energy consumed in these prior art processes is spent not only to overcome natural energy thresholds governed by the material structure features and structural behavior on obtaining specified technical characteristics, but also to overcome uncontrolled (excess) increase in resistance during the uncontrolled action not associated with the material's response to the action and to overcome material condition fluctuations caused by the action upon the material. Thus, when using a “stringent” algorithm, the total energy consumption is more than two times greater than that for overcoming natural energy thresholds of the material structural state upon attaining specified technical effects.
The prior art methods, including the prior art method of ultrasonic impact treatment, are restricted to surface treatment, a stochastic initiation mechanism of random impacts, a non-uniform distribution of the treatment results, limited control of impact parameters, a complex optimization of the impact and a complex adaptation of treatment conditions to the effects on the surface of the material.
As such, the present invention addresses the disadvantages of the prior art technologies, thereby providing a method of adaptive impulse treatment which attains the desired technical effect with minimum energy consumption, optimally distributes the energy in a material and in time, uniformly distributes the specified treatment results in a given volume of the material and the surface thereof. The present invention also addresses the disadvantages of the prior art technologies by providing a method of impulse treatment having controlled impact impulses and adaptation of impulse parameters to the desired technical effect by directly taking into account the response of the material to the action.